Synthesis and conformational analysis of substituted 2,6-dioxabicyclo[3.1.1]heptanes: 1,3-anhydro-2,4-di-O-benzyl-6-deoxy-β-d-glucopyranose by 1H-NMR spectroscopy and molecular mechanics calculation
作者:Xinfu Wu、Fanzuo Kong、Depei Lu、Pang Zhang
DOI:10.1016/s0008-6215(00)90481-6
日期:1992.5
closure of the chloride with lithium methoxide afforded 1,3-anhydro-2,4-di- O -benzyl-6-deoxy-β- d -glucopyranose ( 15 ). Vicinal and long-range proton-proton coupling constants suggested that the conformation of the 1,3-anhydro sugar ether is essentially B 2,5 for the pyranose ring and a chair for the 1,3-dioxane ring. Molecular mechanics calculations using program MMP2 were applied to compound 15 and
摘要甲基3-O-烯丙基-2-O-苄基-4,6-O-亚苄基-α-d-吡喃葡萄糖苷的高选择性开环还原提供了2,4-二-O-苄基衍生物。将其进行甲苯磺酰化或碘化,然后还原,以良好的产率得到结晶的甲基3-O-烯丙基-2,4-二-O-苄基-6-脱氧-α-d-吡喃葡萄糖苷。进行酸水解,再进行脱甲硅烷基化和乙酰化反应,得到1,3-二乙酸酯,将其在乙醚中用氯化氢处理后,得到晶体关键中间体3- O-乙酰基-2,4-二-O-苄基-α-d-吡喃葡萄糖基氯,用甲醇锂将氯化物闭环,得到1,3-脱水-2,4-二-O-苄基-6-脱氧-β-d-吡喃葡萄糖(15)。短程和远距离质子-质子偶合常数表明,1,3-脱水糖醚的构象本质上是B 2。吡喃糖环为5,1,3-二恶烷环为椅子。使用程序MMP2进行的分子力学计算应用于化合物15及其类似物1,3-脱水-2,4-二-O-苄基-β-d-鼠李糖吡喃糖,其结果与通过修饰的方法计算的结果